20978446 has 4 divisors (see below), whose sum is σ = 31467672. Its totient is φ = 10489222.

The previous prime is 20978431. The next prime is 20978473. The reversal of 20978446 is 64487902.

It is a semiprime because it is the product of two primes.

It is a junction number, because it is equal to n+sod(n) for n = 20978399 and 20978408.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5244610 + ... + 5244613.

It is an arithmetic number, because the mean of its divisors is an integer number (7866918).

Almost surely, 2^20978446 is an apocalyptic number.

20978446 is a deficient number, since it is larger than the sum of its proper divisors (10489226).

20978446 is a wasteful number, since it uses less digits than its factorization.

20978446 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10489225.

The product of its (nonzero) digits is 96768, while the sum is 40.

The square root of 20978446 is about 4580.2233569991. The cubic root of 20978446 is about 275.7979950854.

The spelling of 20978446 in words is "twenty million, nine hundred seventy-eight thousand, four hundred forty-six".